This invention relates to a card connector with an eject mechanism for ejecting a card and, in particular, to an improvement of the eject mechanism to increase a stroke for ejecting the card.
It is a recent trend that a portable electronic apparatus, such as a laptop or a notebook-size personal computer and a word processor, is provided with a card connector mounted on a printed circuit board (PCB) as a mother board contained therein. The card connector serves to receive a card-like object, i.e., an electronic card such as a so-called PC card in order to extend a memory capacity and to provide additional functions.
It is noted that the PC card has a size standardized by PCMCIA (Personal Computer Memory Card International Association), JEIDA (Japanese Electronic Industry Development Association), or the like. As the PC card, use has been made of various types of cards such as a memory card for extending a memory capacity, a facsimile modem card for addition of a function of facsimile transmission and reception, an I/O card for connection with a peripheral apparatus. The PC card comprises a small printed circuit board (which will hereinafter be referred to as a "card board") with electronic elements mounted thereon, and a thin plate-type housing containing the card board. The thin plate-type housing (which will hereinafter be referred to as a "card housing") is provided with a connector (which will be referred to as a "card side connector") connected to the card board. The card side connector is mated with the card connector so as to electrically connect the card board with the mother board.
A known arrangement of the card connector comprises a frame defining a card slot for receiving the PC card and having a connector portion. The connector portion is mated with the card side connector of the card received in the slot.
With a growing demand for a wider variety of additional functions provided by the PC card, development has been made of a multi-slot card connector capable of receiving a plurality of PC cards. Typically, a dual-card type is used which receives two cards simultaneously. In the dual-card type connector, the frame defins two card slots for receiving two PC cards, respectively, so that the PC cards are stacked in their thickness directions. Usually, the two card slots are not partitioned but are continuous to each other.
Generally, the card connector adopts an eject mechanism for ejecting the card, in detail, for releasing the mating condition between the card side connector and the connector portion of the card connector. The eject mechanism uses the principle of leverage.
For example, the card connector having the eject mechanism is disclosed in Japanese Unexamined Patent Publications (JP-A) Nos. 9-82411, 6-243299, and 9-115606.
It is noted here that the card connector typically has a contact stroke on the order of several millimeters. The contact stroke is a distance between a contact start position and a contact completion position. The contact start position is a position where, after the card is inserted into the slot of the frame, contact elements of the card side connector are initially brought into contact with contact elements of the connector portion of the card connector. Thereafter, the card is further pushed into the slot towards the contact completion position with frictional sliding between the contact elements of the card side connector and those of the connector portion of the card connector. Thus, complete mating or connection between the card side connector and the connector portion is established where the reliable contact is insured between contact elements of the card side connector and the corresponding contact elements of the connector portion of the card connector. The contact stroke is predetermined in design of the card connector.
In order to remove the card from the card connector, it is necessary at first to release the mating condition against the frictional force between the contact elements of the card side connector and the connector portion of the card connector. Thereafter, the card can be manually removed from the card connector. To this end, the eject mechanism comprises an eject plate slidably mounted on the frame and a lever pivotally mounted on the frame. The eject plate has fingers or detents for engaging with a forward edge of the card edge. The lever has an end slidably and rotatably engaged with the eject plate so that the eject plate is moved to slide on the frame by pivotal rotation of the lever. Thus, the card is pushed by the fingers of the eject plate to be ejected from the mating connection.
The eject mechanism is usually provided with an eject bar or rod so as to rotate the lever. The eject bar has an end which is rotatably engaged with the opposite end of the lever. The eject bar is mounted on the frame and is slidable along the frame. When the eject bar is pushed at the opposite end, it slides along the frame and rotates the lever about the pivot.
In order to eject the card from the mating condition, the eject plate must be moved by a distance which is equal to or more than the contact stroke mentioned above. The distance over which the eject plate is moved by rotation of the lever caused by operating or pushing the eject bar will be referred to as an eject stroke. A distance over which the eject bar is pushed or operated so as to realize the eject stroke through the eject lever will be referred to as an operation stroke. A force pushing the eject bar for moving the eject plate together with the card over the eject stroke through the lever will be operation force.
When the eject stroke is selected to be equal to the contact stroke, there is an actual problem that the card is often moved only a distance insufficiently to release the mating condition between the card side connector and the connector portion of the card connector.
In order to insure eject of the card from the mating condition, it is required to increase the eject stroke. To this end, one way is to use a lever having an increased length. This results in another problem that the card connector itself must have an increased size, because the lever having the increased length would project outside from an outer configure of the frame. Further, the eject bar is required to be pushed over the operation stroke increased for realizing the increased eject stroke.
Another way for increasing the eject stroke is to displace the pivoted position of the lever without increase of the length of the lever. In detail, the lever is pivoted at a point which is far away from the end engaging with the eject plate, that is, further near to the other end engaged with the eject bar. Thus, the leverage is changed so that the eject stroke is increased even if the operation stroke of the eject bar is maintained unchanged. However, the operation force is required to be increased for operating the eject bar to move the eject plate against the friction between contact elements of the card side connector and the connector portion of the card connector.